听读原文：
旁白：Once upon a time there was a mother pig who had three little pigs.
Mother pig: This house is too small. The three of you must leave home and build your own homes.
听读原文： 旁白：Once upon a time there was a mother pig who had three little pigs. Mother pig: This house is too small. The three of you must leave home and build your own homes.
